Semiconductor device having a trench with different electrode materials

Abstract

A semiconductor device includes a semiconductor body having a front side and a back side, and a trench included in the semiconductor body. The trench extends into the semiconductor body along an extension direction that points from the front side to the back side. The trench includes an electrode structure and an insulation structure, the insulation structure insulating the electrode structure from the semiconductor body and the electrode structure being arranged for receiving an electric signal from external of the semiconductor device. The electrode structure includes a first electrode and a second electrode in contact with the first electrode, the first electrode including a first electrode material and the second electrode including a second electrode material different from the first electrode material. The first electrode extends further along the extension direction as compared to the second electrode.

What is claimed is: 
     
       1. A semiconductor device, comprising:
 a semiconductor body having a front side and a back side; and 
 a trench included in the semiconductor body, the trench extending into the semiconductor body along an extension direction that points from the front side to the back side, wherein the trench comprises an electrode structure and an insulation structure, the insulation structure insulating the electrode structure from the semiconductor body and the electrode structure being arranged for receiving an electric signal from external of the semiconductor device, 
 wherein the electrode structure includes a first electrode and a second electrode in contact with the first electrode, the first electrode comprising a first electrode material and the second electrode comprising a second electrode material different from the first electrode material, 
 wherein the first electrode extends further along the extension direction as compared to the second electrode. 
 
     
     
       2. The semiconductor device of  claim 1 , wherein the first electrode material has a first electric conductivity and the second electrode material has a second electric conductivity, the second electric conductivity being higher than the first electric conductivity. 
     
     
       3. The semiconductor device of  claim 1 , wherein a part of the insulation structure is arranged in a bottom region of the trench, the part of the insulation structure having a first insulation zone and a second insulation zone, wherein the first insulation zone is arranged below the first electrode and has a first thickness along the extension direction, and wherein the second insulation zone is arranged below the second electrode and has a second thickness along the extension direction, the second thickness being larger than the first thickness. 
     
     
       4. The semiconductor device of  claim 3 , wherein another part of the insulation structure is arranged above the bottom region of the trench and has a thickness in a lateral direction perpendicular to the extension direction, the first thickness being equal to or larger than the thickness in the lateral direction. 
     
     
       5. The semiconductor device of  claim 1 , wherein the first electrode material comprises polysilicon. 
     
     
       6. The semiconductor device of  claim 1 , wherein the second electrode material comprises at least one of polysilicon and metal.